To determine if anatomic DB ACL reconstruction can effectively restore normal dynamic knee function, we will conduct a double-blind randomized clinical trial to compare SB vs. anatomic DB ACL reconstruction. The specific aims of this study are to determine if DB is better than SB ACL reconstruction in terms of 1) dynamic knee function and 2) clinical outcomes. We will randomly assign 160 subjects with an isolated ACL injury to SB or DB ACL reconstruction and will follow the subjects for 2 years. We will utilize a unique combination of high-speed biplane radiography (for accurate assessment of knee kinematics) and 3D imaging (MRI and CT, to define joint and cartilage morphology) to characterize joint kinematics and cartilage surface interactions during functional tasks. Clinical outcomes will include laxity, range of motion, functional strength and patient-reported symptoms, function and activity. Successful completion of this study will provide evidence of the efficacy of anatomic DB ACL reconstruction for restoring normal knee mechanics and improving clinical outcomes. If the results show a clear benefit of this procedure, then a sound basis will have been established for future studies to assess the benefits of anatomic DB ACL reconstruction on long-term clinical outcomes and joint health.